Mishkat al-Masabih 3 Purification كتاب الطهارة 31

وَعَن عَليّ بن طلق قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسلم: «إِذا فسا أحدكُم فَليَتَوَضَّأ وَلَا تأتو النِّسَاءَ فِي أَعْجَازِهِنَّ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ

‘Ali b. Talq reported God’s messenger as saying, “When any of you breaks wind he should perform ablution, and you must not have intercourse with women by their buttocks.” Tirmidhi and Abu Dawud transmitted it.